| Abstract [eng] |
This paper describes the study of electric motor cooling. As the popularity of electric cars increases, various problems related to them arise, one of them is overheating of the electric motor. An overheated engine is less efficient with its electrical power, the engine can damage other expensive and extremely important components in the electric car, and most importantly, an overheated engine can pose a threat to the driver, passengers, and others, so proper engine cooling is extremely important. The purpose of the study is to examine how the engine design affects the efficiency and cooling of the electric motor. To examine the objectives of the study: to conduct a literature analysis on such methods of cooling electric motors and the cooling means used, to examine the dependence of cooling on the motor design, material, motor rotor material for motor cooling, motor winding, protective epoxy resin for motor cooling, to examine the usefulness of structural motors, to draw conclusions and proposals for the improvement of electric motor cooling. The tests are performed by setting the maximum current to the driving motor and varying the current to the braking motor to simulate the varying load on the driving motor from minimum to maximum load. During the tests, the components of the motor are changed - rotor and epoxy resin. Both rotor and epoxy resin materials have distinct characteristics, so the research will aim to determine how different materials in the motor structure affect the cooling of the electric motor. The study is conducted to determine the best way to cool the engine when they are used for public transportation or cargo transportation purposes. The operating cycles of the engines are urban cycles, they do not require high top speed, but high torque and power are required. Engines are produced in series, so the price of the engine must be low, the engine design must be simple, easy and quick to assemble. Based on the results, the problems of the cooling system or engine design are identified, conclusions are formulated, and proposals are made to solve the identified problems. Problems identified from the obtained results: insufficiently effective cooling system, poorly selected stator cooling channels, materials used in motor production have too low thermal conductivity, poorly selected motor control parameters. During the study, it was found that by changing the components of the engine structure, which are characterized by better thermal conductivity properties, it is possible to obtain a difference of about 3 °C between the best and worst cooled structures. A motor with a copper rotor has been found to perform about 4% more efficiently than a motor with an aluminum rotor in all cases. Recommendations are formulated based on the obtained results: perform calculations of the heat generated by the engine by evaluating the characteristics of all materials used. According to the obtained results, determine the cooling channels of the shape required for the stator and the flow required for the cooling system, so that the cooling system is efficient. Conduct a study using a combination of coolant and oil cooling system and evaluate how the oil affects engine cooling. Judging from the analysis of theoretical solutions, it can be assumed that the oil cooling the motor rotor would significantly reduce the thermal inertia of the motor. Make the necessary corrections to the engine control parameters. Correctly adjusted parameters will reduce the engine load, which affects the engine's efficiency and heat generation. |
