Temperature protecting method of low-voltage plug type bus duct and joint thereof

Abstract

The invention discloses a temperature protecting method of a low-voltage plug type bus duct and a joint thereof, comprising the following steps of: obtaining temperature values of points from an interior to an outer surface of the low-voltage plug type bus duct and the joint thereof by introducing a finite volume method, namely obtaining temperature fields from the interior to the outer surface of the low-voltage plug type bus duct and the joint thereof; by judging whether the maximum temperature value and the environmental temperature difference of the temperature value in the internal points exceed the internal exotherm stipulated by the Chinese standard, ensuring whether the low-voltage plug type bus duct and the joint thereof have faults; and ensuring whether the faults exist by judging whether the surface temperature and the environmental temperature difference exceed the external exotherm stipulated by the Chinese standard. The temperature protecting method overcomes the defect that the traditional bus duct can judge faults by only measuring surface temperature to replace internal temperature, increases possibility for detecting glitch circuits in the bus duct and improves the temperature protection precision of the bus duct.

Description

technical field [0001] The invention relates to the field of temperature control and protection of low-voltage plug-in bus ducts, in particular to a temperature protection method for low-voltage plug-in bus ducts and joints thereof. Background technique [0002] Low-voltage plug-in busway, especially its joints, due to surface oxidation, looseness, poor contact, overload, etc., may cause overheating, insulation breakdown and short circuit, etc., and there will be a small fault current in the system, but Its value may be as small as the instantaneous, long-time delay or even residual current setting value of the circuit breaker at the upper level (at the outlet of the low-voltage power distribution cabinet). At this time, the distribution system will run for a long time under the condition of small fault current. After a certain period of time, the internal temperature of the low-voltage plug-in busway and its joints will be too high due to the accumulation of heat, which wil...

AI Technical Summary

Problems solved by technology

The temperature detected by this technical solution through the temperature sensor is only the outer surface temperature of the busway, and the accuracy of the detected temperature also varies with the relative position of the sensor and the main line of the busway, which cannot meet the national standard GB7251.2-2006 "Low Voltage Complete Set Internal temperature rise detection requirements for bus ducts and their joints in Switchgear and Control Equipment Part 2: Special Requirements for Bus Trunk Systems (Bus Duct)

[0004] The prior art has not reported the relevant technical solutions for judging the internal temperature rise by detecting the temperature of various points inside the low-voltage plug-in busway during actual operation, and taking corresponding protection measures to ensure the safe operation of the power system

Images