Frequency conversion device and voltage transformation method thereof

Abstract

Embodiments of the invention relate to a frequency converter, and disclose a frequency conversion device and a voltage transformation method thereof. In the invention, the frequency conversion devicecomprises the following parts: a plurality of frequency converters; a main control module, electrically connected with each of the frequency converters, and used for phase shifting 1 / N switching cycles required for each frequency converter when the power is turned on, so that the respective PWM pulses required by each frequency converter when the power is turned on are mutually staggered; and a first voltage transformation module, electrically connected to each of the frequency inverters, and used for coupling and superimposing two output line voltages of any two frequency inverters on the same vector edge and the output line voltages of the other frequency inverters in the same direction as the vector edge. Compared with the prior art, medium-voltage frequency converters can be formed byuniversal low-voltage frequency converters, so that the universal low-voltage frequency converters can be fully multiplexed, the frequency conversion device can generate required stable rated voltagesby low technical difficulty and simple control, and development costs and material management costs are also reduced.

Description

technical field [0001] Embodiments of the present invention relate to frequency converters, in particular to frequency conversion devices and voltage conversion methods thereof. Background technique [0002] Medium-voltage frequency converters are widely used in various fans, water pumps, compressors, rolling mills, etc. [0003] At present, medium-voltage inverters mostly use 3300V IGBT devices to form a two-level topology to achieve 1140V frequency conversion output, or use 1700V IGBT devices to form a three-level topology to achieve 1140V frequency conversion output. Or when it is necessary to achieve a higher voltage inverter product such as a 2300V inverter, it is necessary to use more 3300V IGBT devices or 1700V IGBT devices. However, the inventors found that the 3300V IGBT device in the existing market is not a common standard device in the industry, and the cost of the device is high and the delivery time is unstable. The frequency converter developed with 3300V cl...

AI Technical Summary

Problems solved by technology

However, the inventor found that the 3300V IGBT device in the existing market is not a commonly used standard device in the industry, and the cost of the device is high and the delivery time is unstable

The inverter developed with 3300V class IGBT devices has poor output voltage characteristics, high voltage distortion, and large dudt value

Using 1700V class IGBT for multi-level development, complicated control, high technical difficulty and high R&D cost

Moreover, the introduction of new devices and the development of new products have poor material reusability, and the original mature technology of low-voltage products is also difficult to reuse, which increases material operating costs and product operating costs.

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