Variable-frequency control circuit, variable-frequency air conditioner control circuit and variable-frequency air conditioner

Abstract

The invention provides a variable-frequency control circuit, a variable-frequency air conditioner control circuit and a variable-frequency air conditioner. A switch module and an alternating-current voltage detection module are arranged on the alternating-current input side; a direct-current voltage detection module, which is used for detecting the charging voltage of a filter module, is arrangedon the direct-current side; an MCU controls the switching states of the switch module to be switched according to the alternating-current voltage VC detected by the alternating-current voltage detection module and the direct-current voltage value VD detected by the direct-current voltage detection module, so that the filtering module on the direct-current side is controlled to be charged, and theVC-VD is controlled to be lower than a preset voltage value delta V; therefore, the charging current in a charging loop is ensured to be below the safety value, so that the impact on the device in thecharging loop is avoided; and meanwhile, compared with a condition that an existing PTC resistor and a relay are needed to be set singly for performing current limitation on the charging of the filtering module, the PTC resistor can be omitted in the invention, so that the size of the whole variable-frequency control circuit is reduced, and the cost is lowered.

Description

technical field [0001] The invention relates to the field of frequency conversion control, in particular to a frequency conversion control circuit, a frequency conversion air conditioner control circuit and a frequency conversion air conditioner. Background technique [0002] At present, frequency conversion controllable circuits, such as household appliances used in frequency conversion loads such as frequency conversion household air conditioners, are loaded with frequency conversion compressors and DC motors. The capacity is very large, such as more than 800uF, so the current is very large when charging it. In order to prevent the charging current from being too large, generally a PTC resistor is connected in series on the AC input side and a relay is connected in parallel. Charging, the relay is disconnected after the charging is completed, so a high-power PTC resistor needs to be added, which occupies the volume of the entire control circuit. Further, when it is applie...

AI Technical Summary

Problems solved by technology

[0004] The main purpose of the present invention is to provide a frequency conversion control circuit, which aims to solve the problems of occupying volume and increasing cost due to the need to separately set the PTC resistance for charging the electrolytic capacitor

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