Overvoltage protection device for air conditioner, overvoltage protection method and air conditioner

Abstract

The invention discloses an overvoltage protection device for an air conditioner. The overvoltage protection device comprises a PTC (Positive Temperature Coefficient) thermistor, a controllable switch, a voltage sampler, an electrolytic capacitor, a temperature detector and a control module, wherein the controllable switch is connected in parallel with the PTC thermistor; the voltage sampler samples direct current voltage output by a rectifier; the temperature detector detects environment temperature in real time; and the control module controls the controllable switch to disconnect when the direct current voltage is greater than preset safe voltage to allow the PTC thermistor to be connected in series with a power supply circuit, acquires safe recovery voltage according to the current environment temperature when operating frequency of a compressor is less than or equal to first preset frequency, and controls the controllable switch to close to allow the PTC thermistor to be short-circuit. The overvoltage protection device can perform overvoltage protection when input alternating current voltage is too high, and avoids damage of an electronic component in the air conditioner due to overvoltage. The invention further discloses the air conditioner and an overvoltage protection method thereof.

Description

technical field [0001] The invention relates to the technical field of air conditioners, in particular to an overvoltage protection device for an air conditioner, an air conditioner with the overvoltage protection device, and an overvoltage protection method for the air conditioner. Background technique [0002] At present, when the inverter air conditioner is powered by AC mains, the AC mains is converted into DC by a rectifier and filter circuit and then supplied to the IPM module. [0003] However, due to voltage fluctuations in the AC power grid, the voltage of the AC mains input to the rectifier circuit will increase, so the voltage of the DC output from the rectifier circuit will also increase accordingly. The safety value of withstand voltage is certain, and when the operating voltage of these devices exceeds its maximum withstand voltage value, the working performance of these devices will be reduced or even damaged. For example, the parameter of the high-voltage fi...

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Problems solved by technology

[0003] However, due to voltage fluctuations in the AC power grid, the voltage of the AC mains input to the rectifier circuit will increase, so the voltage of the DC output from the rectifier circuit will also increase accordingly. The safety value of withstand voltage is certain, and when the working voltage of these devices exceeds its maximum withstand voltage value, the working performance of these devices will be reduced or even damaged

For example, the parameter of the high-voltage filter capacitor is 400UF / 400V. When the AC power grid is unstable, if the voltage of the AC mains rises greatly, the voltage loaded on this capacitor will exceed 400V for a period of time, which will cause its capacitance to drop or even Damaged by short circuit

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