Mixed ventilation cooling system and method for permanent magnet traction motor

Abstract

The invention relates to a mixed ventilation cooling system and method for a permanent magnet traction motor. The cooling system consists of a radial ventilation cooling system and an axial ventilation cooling system which are independently driven to work, the radial ventilation cooling system is used for directly blowing and cooling a rotor and a permanent magnet, and the axial ventilation cooling system is used for cooling an end winding and balancing the temperature rise of the whole motor. According to the system and the method, radial ventilation and axial ventilation are separated in terms of mass transfer, and the wind resistance loss of the ventilation systems is relatively low; seriously heated positions in the motor are cooled by the two sets of ventilation systems respectively, so that high cooling performance is achieved; the radial ventilation cooling system is divided into two parts, namely, an air inlet passage and an air outlet passage, by a separation plate, and the temperature rise of cooling air entering each radial air vent is similar, so that axial balance of the temperature rise of the motor is ensured; circumferential balance of the temperature rise of the motor is ensured by the axial ventilation cooling system. The system and the method have the characteristics of good motor interior cooling effects and good motor temperature rise balance, and are suitable for popularization and application.

Description

technical field [0001] The invention relates to the technical field of motor manufacturing, mainly to a motor cooling system, in particular to a cooling system for a permanent magnet traction motor of small and medium-sized rail transit, public transportation, and electric vehicles, specifically to a cooling system with two sets of axial and radial ventilation paths. A permanent magnet traction motor cooling system and method. Background technique [0002] Permanent magnet motors have the characteristics of high efficiency and high power density, and can maintain high efficiency and power factor under light-load operation conditions. Compared with asynchronous motors as traction motors, they can effectively save energy in the long-term operation of electric vehicles. . Since the electric vehicle motor is controlled by a frequency converter and the operating frequency is often high, there are a large number of space harmonics and time harmonics in the motor rotor and permane...

AI Technical Summary

Problems solved by technology

In addition, due to the needs of the installation process and production process, there is a large gap between the permanent magnet and the installation slot opened in the rotor core, which affects the heat transfer of the permanent magnet.

The indirect cooling efficiency of the traditional permanent magnet motor axial ventilation system for the permanent magnet is low, and it is difficult to guarantee its heat dissipation capacity

However, in the mixed ventilation structure of asynchronous motors in the past, the radial air path and the axial air path are cross-linked, and the wind resistance loss of small and medium-sized traction motors is relatively large, which limits the efficiency of the motor.

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