Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Protection method for motor ground fault in frequency converter and frequency converter

A ground fault and frequency converter technology, applied in the field of frequency converters, can solve the problems of no ground fault protection, large IGBT damage, IGBT failure, etc., and achieve the effects of ensuring accuracy, accurate judgment results, and prolonging service life.

Pending Publication Date: 2019-08-20
ZHEJIANG CHINT ELECTRIC CO LTD
View PDF0 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There is a problem here: even if the motor ground fault protection is realized by detecting the current after the inverter is running, the damage to the IGBT is still relatively large. If the number of times is too high, the IGBT will fail, and even the IGBT will be directly damaged if the protection is not timely (insulated gate double). polar transistor) case
Moreover, the existing low-power inverters do not have ground fault protection

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Protection method for motor ground fault in frequency converter and frequency converter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0023] The following is attached figure 1 The given examples further illustrate the specific implementation of the frequency converter of the present invention. The frequency converter of the present invention is not limited to the description of the following embodiments.

[0024] The frequency converter of the present invention adopts the protection method for the grounding fault of the motor in the frequency converter of the present invention, the frequency converter includes an IGBT circuit, a charging resistor and a relay connected in parallel with the charging resistor, the IGBT circuit includes a U-phase IGBT unit, a V-phase IGBT unit and a W-phase IGBT unit, each IGBT unit includes an IGBT upper bridge Q1 and an IGBT lower bridge Q2; it is characterized in that: the gate G of each IGBT upper bridge is connected to the output end of an optocoupler PC1, each The gate G of each IGBT lower bridge Q2 is connected to the output terminal of an optocoupler PC2, and the input ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to the technical field of power electronics and particularly relates to a protection method for a motor ground fault in a frequency converter. After the frequency converter is powered on and a relay is connected, the turn-on time t of an IGBT lower bridge Q2 of each phase IGBT unit or the simultaneous turn-on time t of the IGBT lower bridge Q2 or an IGBT upper bridge Q1 of each phase IGBT unit is allowed to be larger than 0 and smaller than 10 microseconds, whether the motor in the frequency converter has a ground fault is judged according to the output current of each phase IGBT unit, the operation is simple, the judgment is accurate, and an IGBT circuit is not damaged. The invention also discloses a frequency converter applying the above protection method, the circuit structure is simple, whether the motor has a short circuit fault can be accurately and accurately determined, and the IGBT circuit of the frequency converter is not damaged.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a protection method for a motor ground fault in a frequency converter, and also to a frequency converter applying the above protection method. Background technique [0002] Inverter is the key equipment to transform the industrial frequency power supply (50Hz / 60Hz) into AC power supply of various frequencies to realize the variable speed operation of the motor. The frequency converter can reduce the voltage fluctuation of the power line, reduce the impact on the power grid, avoid the problem of excessive peak-to-valley difference, and can also control the starting current of the motor, reducing the maintenance cost of the motor; [0003] With the maturity of inverter technology, reliable protection functions have become the core competitiveness of inverters. At present, the motor ground fault protection of the frequency converter on the market is protected by detecting...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): H02H7/085H02P27/04
CPCH02H7/085H02P27/04
Inventor 陈伟孟董海亮
Owner ZHEJIANG CHINT ELECTRIC CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com