Low-loss arc-free composite multifunctional DC contactor

Abstract

The invention relates to a low-loss arc-free composite multifunctional DC contactor. The structure is as follows: an input anode bus in an external power circuit is simultaneously connected with one end of a protective capacitor C of an IGBT tube, a collector C of the IGBT tube and an input end of a contactor K; an output anode bus in the external power circuit is simultaneously connected with the other end of the protective capacitor C of the IGBT tube, a drain E of the IGBT tube and an output end of the contactor K; one end of a current and voltage transmitting circuit is connected with the input anode bus and the output anode bus in the external power circuit and the other end is connected with an AD sampling port of a microprocessor circuit; one end of a contactor drive circuit is connected with a contactor solenoid and the other end is connected with an end S1 of the microprocessor circuit; and two ports of one end of an IGBT tube drive circuit are connected with ends G and E of the IGBT tube respectively and the other end is connected with an end S2 of the microprocessor. The low-loss arc-free composite multifunctional DC contactor has the advantages of being free of an arc in breaking, short in break time, high in impact current resistance, low in loop loss, small in heat, small in size and the like.

Description

technical field [0001] The invention relates to a composite contactor used for solar DC power supply and other DC power supply breaking, in particular to a low-loss and arc-free composite multifunctional DC contactor. Background technique [0002] With the development of power electronics technology, both the power distribution system itself and the final power users are increasingly using DC power distribution or power consumption equipment. On the power source side, distributed power sources are mainly photovoltaic power generation, wind power generation, fuel cells and micro gas turbines. The power generated by these power sources is DC or converted to DC through simple rectification. If these DC power are directly integrated into the DC distribution network, it will save A large number of commutation links are removed, which also reduces power consumption. DC power distribution lines have low loss, high transmission efficiency, and save line corridors; compared with tra...

AI Technical Summary

Problems solved by technology

[0003] Among them, the DC contactor disconnects the load from the DC circuit through mechanical action. Due to the mechanical breaking of DC, an arc will be generated, and the larger the current and the higher the voltage, the more difficult it is to extinguish the arc, which requires a larger configuration space for the DC contactor. In the arc extinguishing chamber; and the existence of the arc prolongs the breaking and breaking time of the device; the high temperature generated by the arc will melt and evaporate the contact surface, burn out the insulating material, and may cause the surrounding combustible gas and combustible materials to burn, resulting in fire or explosion and other dangers; because the arc moves under the action of electric power and heat, it is easy to cause arcing short circuit and hurt people or cause the accident to expand

[0004] DC electronic switches include the following categories: high-power triodes, IGBT tubes, field effect tubes, and solid-state relays. Due to the PN node voltage drop in the conduction of DC electronic switches, a large amount of power will be lost under long-term power-on conditions. Electric energy accumulates heat, and it will reduce the transmission efficiency. If there is a large capacitive load and a large current impact when starting, it may cause overcurrent breakdown of the PN node and cause system instability. In order to dissipate the electronic switch when it is working For the accumulated heat, a heat sink must be installed on the electronic switch for passive cooling or active cooling in the heat sink + fan mode, which increases the size and system complexity of the electronic switch

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