Motor Winding Temperature Rise Unqualified Reason Analysis

Motor Winding Temperature Rise Unqualified Reason Analysis

For different series of motors, the design of the temperature rise margin is different; for the same series of motors, may be due to power, installation, parts commonality and many other factors, there will be a very tight physical space. Motor temperature rise does not comply with the general only in the type test and operation process can be found, leading to the motor temperature does not meet the reasons, can be checked and analysed from the loss and ventilation.

When the stator current and stator copper loss is large, it will lead to high motor temperature rise, and the rotor copper loss and iron core will also directly affect the motor temperature rise. For ventilation losses, in most cases it is necessary to reduce the temperature rise. Related losses in the design process will be the overall effect of the balance, but also through the balance of material usage for the overall cost of the relationship between the disposal.

For how to adjust and reduce motor losses, we have also carried out a more detailed analysis in the previous content, this paper will not repeat, but when the loss and design and pre-type test data have a large deviation, should be specifically analysed.

Motor products, the wind path has a greater impact on the temperature rise of the motor, motor fan, wind cover, cast aluminum rotor wind blade, the inner fan, stator winding end dimensions, with radial ventilation channel motor ventilation channel, stator and rotor alignment, etc. will affect the ventilation effect of the motor.

The wind pressure and air volume generated by the rotor fan are limited by the structure and efficiency of the motor, keeping the wind path smooth and reducing the wind resistance can increase the wind volume; adjusting the ratio of wind resistance of the parallel wind path can reasonably distribute the wind volume. Properly adjust the shape, position and size of ventilation components to prevent local circulation or ineffective circulation of airflow can effectively reduce the temperature rise of the motor.

A large part of the heat of the stator winding of the protective motor is dissipated from the end. Centrifugal fans should be located as close as possible to the centre of the stator winding ends so that the cooling air can effectively cool the winding ends. The cast aluminium rotor fan blades should have a proper radial clearance from the end of the stator winding, and a too narrow air path will reduce the amount of air on the end surface of the winding. Scattered embedded stator winding end, especially high speed motor effect is more obvious.

Motor with radial ventilation channel, if the core length of each section does not match the drawing, the seat, rotor shaft, end caps and other axial dimensions of the processing error is too large, will cause the stator and rotor core ventilation slot on the alignment of the rotor air duct spacer generated by the airflow is difficult to enter the stator ventilation slot. Stator and rotor core processing process of radial ventilation channel distortion, the motor temperature rise of the impact is particularly serious.

In addition to the stator and rotor core and winding factors, the seat cavity, the shape and size of the heat dissipation window, as well as with each other, also has a greater impact on the motor air circuit.

Wind is one of the larger factors affecting the performance of the motor product, especially for motor temperature rise and noise performance is more obvious, but precisely in the design and control of the wind road, most manufacturers ate is not very penetrating, such as the direct migration of the casting chassis programme to the box-type chassis programme, the mechanical dimensions of the coordination of conformity, do not necessarily ensure that each other's consistency of the wind road, the research in this area needs to be further in-depth.