Overcurrent protection device and method for frequency converter, and frequency converter

Abstract

The invention discloses an overcurrent protection device and method for a frequency converter, and the frequency converter. The device comprises: a sampling unit which is configured to sample the current parameter of the frequency converter, and based on the bias voltage provided by the bias voltage chip, processing the current parameter to obtain a current sampling parameter used for determining whether the frequency converter is over-current, a protection unit configured to set a protection parameter range for performing overcurrent protection on the frequency converter according to the current parameter of the frequency converter; and a control unit configured to determine whether the current sampling parameter exceeds the protection parameter range or not by judging the level of the current sampling parameter, and if the current sampling parameter exceeds the protection parameter range, start a preset overcurrent protection mechanism. According to the scheme, the reliability of overcurrent protection of the frequency converter can be improved by improving the current sampling precision of the frequency converter.

Description

technical field [0001] The invention belongs to the technical field of frequency converters, and in particular relates to a frequency converter overcurrent protection device, method and frequency converter, in particular to a high-power frequency converter current sampling and hardware overcurrent protection device, method and frequency converter. Background technique [0002] Overcurrent (that is, overcurrent) means that the current of a motor or electrical component exceeds its rated current. Overcurrent is a very important factor affecting the safe operation of high-power inverters, and even poses a huge threat to the personal safety of the inverter and operators. Therefore, it is necessary to sample the current of the inverter and perform overcurrent protection. However, if the current sampling accuracy of the frequency converter is low, it will affect the reliability of the overcurrent protection of the frequency converter. [0003] The above content is only used to a...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a frequency converter overcurrent protection device, method and frequency converter, to solve the need to perform current sampling on the frequency converter in the overcurrent protection of the frequency converter, if the current sampling accuracy of the frequency converter is low, It will affect the reliability of the inverter's over-current protection, improve the current sampling accuracy of the inverter, and improve the reliability of the inverter's over-current protection

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