DC bus-bar voltage collection method for frequency changer

Abstract

The invention provides a direct current bus voltage acquisition method for a frequency converter. The acquisition method is performed in a flyback switching power supply of the frequency converter by the following two steps: step one, the bus voltage is connected with a primary side of a transformer of the switching power supply; and step two, a voltage acquisition circuit is connected with a secondary side of the transformer by applying a forward mode, and finishes the acquisition of direct current bus voltage. The method ensures that a direct current bus voltage circuit and the voltage acquisition circuit are isolated, and the isolation directly improves the safety and reliability of an acquisition mode of the bus voltage and also reduces the fault rate of a bus voltage acquisition circuit. The method utilizes the characteristic that the switching power supply is universally applied to frequency converters, and the realization of the technical proposal does not need to increase production cost.

Description

technical field [0001] The invention relates to a DC bus voltage acquisition method, in particular to a DC bus voltage acquisition method used on a frequency converter. Background technique [0002] According to a report by China Jiangxi News Network on November 12, 2007, industrial electricity consumption accounts for 60% of the electricity consumption of the whole society. In the current international and domestic energy shortage situation, reducing the electricity consumption of industrial electrical appliances has become the energy saving of the whole society. The first choice, and frequency conversion technology can realize the energy-saving needs of industrial electrical appliances, this technology can be widely used in industrial electrical products. The frequency conversion technology is characterized by adjusting the power frequency to a continuously adjustable frequency according to the operation requirements of the product, which is suitable for stepless and smoot...

AI Technical Summary

Problems solved by technology

[0003] The acquisition technology of the DC bus voltage in the frequency converter is one of the necessary conditions to realize the frequency conversion algorithm. The voltage acquisition circuit is directly connected to the bus voltage. This acquisition method has poor safety performance, and the voltage acquisition circuit is not only complicated but also has a high failure rate.

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