Intelligent short-circuit protection switching circuit for corrective wave inverter

Abstract

The invention discloses an intelligent short-circuit protection switching circuit for a corrective wave inverter. The circuit comprises a PFC boosting unit and a short-circuit switching unit. The input end of the short-circuit switching unit is connected with the output end of the PFC boosting unit. The short-circuit switching unit is used for driving the switch-on or switch-off of the input end and the output end based on the electric signals received by the control end of the short-circuit switching unit. The circuit further comprises an inverting unit, a current sampling circuit and an intelligent recognition unit. The intelligent recognition unit is used for receiving the current signals collected by the current sampling circuit, and when the current signals do not surpass a preset value, the intelligent recognition unit sends a switch-on electric signal to the control end of the short-circuit switching unit to make the short-circuit switching unit drive the input end and the output end to switch on. When the current signals surpass the preset value, the intelligent recognition unit sends a switch-off electric signal to the control end of the short-circuit switching unit to make the short-circuit switching unit drive the input end and the output end to switch off. The intelligent short-circuit protection switching circuit for the corrective wave inverter can enhance the capacity of carrying capacitive loads of the inverter, and avoid the mistaken switch-off or mistaken damage of the inverter.

Description

Technical field [0001] The invention relates to a protection circuit of an inverter, in particular to an intelligent short-circuit protection switch circuit of a modified wave inverter. Background technique [0002] In the prior art, common modified sine wave inverters and AC-to-AC modified sine wave inverters are directly boosted and filtered before being sent to the inverter circuit. There is no buffer circuit in between. When the output end of the inverter circuit is impure In the case of resistive load, a peak current that is several tens of times higher than the normal load will be generated on the switch tube of the inverter circuit, which usually causes the inverter to fail to carry a non-capacitive load and cause false shutdown. Moreover, the inverters in the prior art rely on the performance of the inverter switching device itself to withstand the impact of current, so it is easy to cause false shutdown or damage the switching tube, which greatly increases the damage rat...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, common modified wave inverters and AC-to-AC modified wave inverters are directly boosted and filtered before being sent to the inverter circuit without a buffer circuit in between. When the load is resistive, the switch tube of the inverter circuit will generate a peak current dozens of times higher than the normal load, which will usually cause the inverter to not be able to take the non-capacitive load and cause a false shutdown

Moreover, the inverters in the prior art all rely on the performance of the inverter switching device itself to withstand the impact of the current, so it is easy to cause false shutdown or damage to the switching tube, which greatly increases the damage rate and cost of the switching device.

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