Influence of work environment on thermal state of electric mine motors

Abstract

Influence of work environment on thermal state of electric mine motors The paper presents a model for calculations of the temperature field in electric mine motors with a water cooled frame. That model was worked out with use of modified and improved thermal networks developed by the author for determining the temperature distributions in different types of ac machines. Thermal calculations for a selected type of 400 kW mining motor were performed with use of an original computer program. Their results were compared with those obtained from measurements. On the basis of the verified simulation results there was determined the influence of value changes of parameters characterising the work environment condition (ambient temperature, inlet temperature and cooling water discharge, degree of covering the casing with coal dust) on the mining motor thermal state.

The model of double-cage induction motor for the analysis of thermal fields in transient operations

“…It generates a high cost, which explains why a relatively small number of publications is currently being devoted to experimental research on heating problems in high-power squirrel cage induction motors [7][8][9][10]. This type of research is generally limited to steady-state operations.…”

Electric mine motor thermal models aiding design and setting thermal protections

“…Computer programs for calculations of the temperature field in mine motors in the steady and transient thermal states developed on a basis of the modified thermal networks are also used when designing motors and investigating hazards occurring in motors during exploitation under different environmental conditions existing in coal mine undergrounds [14], for instance increased ambient or cooling water temperature, decreased cooling water discharge, covering the motor casing with coal dust.…”

“…The new equivalent thermal diagram for a medium stream flowing in a cooling duct divided into difference elements developed by the author [13,14] represents the nonlinear temperature distributions in the streams of water and air flowing in cooling ducts of mine motors under steady and transient thermal conditions. It enables the joint modelling of phenomena occurring in the motor construction elements and streams of cooling media flowing in them when taking into account an interaction between them.…”

“…It has enabled modelling two-, even three-dimensional temperature distributions in electric machines when taking into account nonlinear temperature distributions in medium streams flowing through cooling ducts as well as heat accumulation occurring in them in transient thermal states [13,14].…”

Improvement of the Thermal and Mechanical Strength of the Starting Cage of Double-Cage Induction Motors

“…This entails high experimental costs. Therefore, there are relatively few publications addressing experimental research related to the heating of high-power cage induction motors [20][21][22].…”