Unlock instant, AI-driven research and patent intelligence for your innovation.

Motor thermal overload protection method

A technology for electric motors and thermal overload, applied to emergency protection circuit devices, electrical components, etc., can solve problems such as increased calculation, difficult processing, and errors

Active Publication Date: 2014-02-26
BEIJING SIFANG JIBAO AUTOMATION +1
View PDF3 Cites 8 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] (c) Formula (1) contains a logarithmic function, which is difficult to handle
It is often necessary to use some approximate algorithms such as Taylor expansion and curve fitting to calculate the logarithmic function, which causes a certain degree of error and increases the amount of calculation

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
  • Motor thermal overload protection method
  • Motor thermal overload protection method
  • Motor thermal overload protection method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0033] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0034] as attached figure 1 As shown, a three-phase current transformer is installed on the motor power supply line. The motor protection device obtains the three-phase current of the motor from the secondary side of the three-phase current transformer.

[0035] As mentioned in the background technology, the national standard GB / T 14598-15-1998 of the People's Republic of China for electric thermal relays stipulates that the thermal characteristics of the motor thermal overload protection are as follows:

[0036] t = τ ln I 2 - I P 2 I 2 - ( k ...

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 discloses a motor thermal overload protection method. The method comprises the following steps: (1), acquiring the load current of a motor, and calculating an equivalent current Ieq; (2), calculating the heat accumulation value of the motor at the moment according to a formula expressed in the descriptions, wherein theta[*k] is the heat accumulation value of the motor at the moment, theta[*k-1] is the heat accumulation value calculated last time, I[*k] is a ratio of the equivalent current Ieq at the moment to a starting current fixed value Iset, tau is a motor heating time constant, and delta t is a calculated time interval; (3), when the heat accumulation value theta[*k] reaches p, performing thermal overload protection alarm, wherein o<p<1; and (4), when the heat accumulation value theta[*k] reaches 1, tripping at a thermal overload protection outlet. By using the method provided by the invention, the heat accumulation of the motor before thermal overload can be calculated, the thermal overload state of the motor can be better reflected, and the method also has the advantages of simple calculating, stable and reliable simple algorithm, simple and easy realization and the like.

Description

technical field [0001] The invention belongs to the technical field of relay protection, and in particular relates to thermal overload protection of a motor. Background technique [0002] The national standard GB / T 14598-15-1998 of the People's Republic of China for electric thermal relays specifies the thermal characteristics of thermal overload protection for motors as follows: [0003] t = τ ln I 2 - I P 2 I 2 - ( k * I B ) 2 - - - ( 1 ) ...

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
IPC IPC(8): H02H7/085
Inventor 董杰李继晟苏毅朱启晨邹卫华秦应力杨志贤刘全
Owner BEIJING SIFANG JIBAO AUTOMATION
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

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

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com