Driving and protecting circuit for inversion module

Abstract

The invention belongs to the technical field of frequency converters and relates to a driving and protecting circuit for an inversion module. The circuit comprises a driving circuit, an overvoltage clamping circuit, a gate voltage reduction circuit, a soft turn-off circuit and an overcurrent protection circuit; the gate voltage of the inversion module is clamped to be in a specific voltage range through the overvoltage clamping circuit, and therefore, the problem that the inversion module is damaged due to over-high gate voltage in case of over-high current is solved; the gate voltage of the inversion module is reduced through the gate voltage reduction circuit; and the soft turn-off circuit performs soft turn-off on the inversion module before a driving optocoupler is not blocked; under the condition that the gate voltage reduction circuit or the soft turn-off circuit works, overlarge current signals can be fed back to an upper computer controller through an isolation optocoupler, anddriving signals are blocked, and therefore, the inversion module is prevented from repeatedly performing overlarge current protection on the inversion module. Compared with an intelligent optocouplerdriving circuit, the driving and protecting circuit of the invention is lower in cost. Compared with a common optocoupler driving circuit, the driving and protecting circuit is more stable and reliable.

Description

technical field [0001] The invention belongs to the technical field of frequency converters, in particular to an inverter module drive and protection circuit. Background technique [0002] With the development of electronic technology, the application of inverter modules is becoming more and more extensive, especially inverter modules are essential core components in frequency converters and inverter products. As long as the components are abnormal, such products are almost equivalent to being scrapped. Therefore, the drive and protection circuit of the inverter module has been given due attention in the design of the inverter product. It can be seen that the stability and reliability of the drive circuit of the inverter module directly affects whether it can work normally. At present, the way to drive the inverter module is mostly to use an optocoupler to drive through isolation. There are two types of drive optocouplers on the market: ordinary drive optocouplers and intel...

AI Technical Summary

Problems solved by technology

Ordinary optocouplers only provide drive and undervoltage protection capabilities, while smart optocouplers have over-current protection functions, soft-off functions, etc. in addition to the functions of ordinary optocouplers. figure 2 As shown, but the cost of intelligent optocoupler is relatively high, and the cost of using intelligent optocoupler on the medium and low power inverter models far exceeds the budget range of product design

[0003] However, most of the current users tend to pursue exquisite, cheap and compact industrial products. In order to meet customer requirements and reduce product costs, many inverter product manufacturers continue to compress the volume of products and reduce the protection functions that products should have.

Especially in the design of small and medium power products, many manufacturers are trapped by the pressure of cost. When designing the drive circuit of the inverter module in the product, they directly adopt the traditional design concept and use the ordinary drive optocoupler to replace the intelligent optocoupler. , do not do any protection treatment, so that the inverter module is in an unprotected state, which will have great defects and hidden dangers for the product itself

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