Frequency converter protection device, frequency converter and air conditioner

A technology for protection devices and frequency converters, applied in the field of frequency converters, can solve the problems of expensive DC relays, no control loop abnormality detection function, failure to detect failure of frequency converter protection and control in time, etc., to achieve lower requirements, reliable disconnection, and extended disconnection the effect of time

CN113922336APending Publication Date: 2022-01-11QINGDAO HISENSE HITACHI AIR CONDITIONING SYST
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2022-01-11

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Abstract

The invention discloses a frequency converter protection device, a frequency converter and an air conditioner. The frequency converter protection device comprises: a first switch unit and a second switch unit; a first switching branch; a second switch branch circuit, wherein the second switch branch circuit and the first switch branch circuit are connected in parallel between the P+ end and the P- end of the bus; and a self-checking circuit, wherein the detection end of the self-checking circuit outputs a detection signal. After the frequency converter is powered on, the main controller of the frequency converter firstly controls the first switch unit, so that the first normally open contact is closed, and the bus is charged; before bus charging reaches a preset voltage value and a motor is started, controlling a second switch unit to enable a second normally open contact to be closed, enabling the motor to enter a pre-starting stage, and monitoring a detection signal at the same time; when the frequency converter is shut down normally, the motor is stopped firstly, and the relay is disconnected after the current of the relay and the voltage between the normally open contacts are reduced; and when the second coil is abnormal, the relay is disconnected after the frequency converter is shut down. The frequency converter protection device is arranged on the direct current bus side, and pull-in and reliable disconnection of the relay under small current can be achieved.
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Description

technical field

[0001] The invention relates to the technical field of frequency converters, in particular to a frequency converter protection device, a frequency converter and an air conditioner. Background technique

[0002] Frequency converters are widely used in the air-conditioning industry. In order to improve the reliability of the frequency converter itself, the frequency converter usually has an overcurrent protection function, which is used to cut off the current of the frequency converter in a timely and reliable manner when the frequency converter needs to be protected.

[0003] If it is desired to reliably disconnect the power supply line of the inverter in any state (especially in the case of high voltage and high current), there are generally two ways to cut off the current of the inverter: 1. On the input power side of the inverter Cut off the current; 2. Cut off the current at the P+ / P- of the DC bus side of the inverter.

[0004] The current is cut off on ...

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Embodiment Construction

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention.

[0045] Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. In describing the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientations or positional relationships indicated by "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than in...